A while back I decided to make a temperature-controlled box for ales. I was hesitant to post until I fermented a couple in it. It works GREAT! I basically built a wooden frame out of wood and nailed insulation to it. I cut a little hole in the side and propped a little heater-fan from Lowes next to it.

I also took a mini-fridge and hooked it up to an appliance timer.

I calibrated the temperatures by using a cheap remote grill thermometer and putting it in a brew-bucket full of water and slowly adjusted the fan dial and spacing for the ale box and the appliance timer on the mini fridge over about a week until I sustained the temperature I wanted.

5 brews later, they hold their temperatures pretty steady. I don't even worry about the mini fridge, it hasn't dropped more than a degree since I calibrated it.

Welcome to our obsession.
You must take pics and post them up.
Cheers.
Looking forward to trying a few of those at a meeting.

Interesting John. I do like DIY projects.

Here is a picture with the inside and the outside showing.